1. Technical Field
The present invention relates to a laser device, a laser device manufacturing method, a laser device array, a light source, and a light module.
2. Related Art
An oxide layer formed by selectively oxidizing a semiconductor layer containing Al has been conventionally used as a current confinement layer for confining current flowing through an active layer of a surface emitting laser device. In order for the surface emitting laser device to operate at high speed, it is necessary to decrease the capacitance of the oxide layer. The capacitance of the oxide layer is inversely proportional to the thickness of the oxide layer. To achieve this, a method that increases thickness of the insulating layer by implanting ions in the periphery of the oxide layer and a method that increases thickness by forming a tapered oxide layer have been proposed, as shown in Patent Document 1 and Non-Patent Document 1, for example.
Patent Document 1: US patent Application No. 2009/0262765
Non-patent Document 1: Journal of Selected Topics in Quantum Electronics vol. 5, p 553, 1999
However, the ion implantation method is a complex process, and is therefore bad for manufacturing yield. Furthermore, an oxide layer with a tapered shape includes an inflection point at which the slope changes non-continuously at an interface between the tapered portion and the flat portion, and therefore the oxide layer is easily broken due to thermal stress being focused at the inflection point.